Mouse events for an openGL window

I'm trying to implement an UI in my openGL window interface
and trying to handle the mouse events (for now before doing the keyboard events)
I get the mouse down/up events without any problems.
and the mouse Moved ok (if a button is not down).
but I do NEVER get the mouseDragged event or a mouseMoved event
if my mouse button is down.

I'm looking at TrackingLocation but seems complex for what I want to do,
don't really need multi-threading for now ...

well I don't even get the mouseDragged event ...
I do get the mouseDown event but after this one,
no MouseMoved or MouseDragged event until I release
the button (MouseUp) then I get MouseMoved events again ...

I did write a first experiment some time ago using a full screen
window and got the mousedragged event , and I use the
exact same code for event handling ... so I guess that dragged
event doesn't make it to my handler :/

sorry don't have my source code right here...
I'll post it later today.